cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sigio.c (961B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
      4 */
      5
      6#include <linux/interrupt.h>
      7#include <irq_kern.h>
      8#include <os.h>
      9#include <sigio.h>
     10
     11/* Protected by sigio_lock() called from write_sigio_workaround */
     12static int sigio_irq_fd = -1;
     13
     14static irqreturn_t sigio_interrupt(int irq, void *data)
     15{
     16	char c;
     17
     18	os_read_file(sigio_irq_fd, &c, sizeof(c));
     19	return IRQ_HANDLED;
     20}
     21
     22int write_sigio_irq(int fd)
     23{
     24	int err;
     25
     26	err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
     27			     0, "write sigio", NULL);
     28	if (err < 0) {
     29		printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
     30		       "err = %d\n", err);
     31		return -1;
     32	}
     33	sigio_irq_fd = fd;
     34	return 0;
     35}
     36
     37/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
     38static DEFINE_MUTEX(sigio_mutex);
     39
     40void sigio_lock(void)
     41{
     42	mutex_lock(&sigio_mutex);
     43}
     44
     45void sigio_unlock(void)
     46{
     47	mutex_unlock(&sigio_mutex);
     48}